1. Field of the Invention
This invention relates to reflectors for delineating, for example, highway traffic lanes and road edges, and more particularly to reflectors of the kind to be placed in spaced linear relationship along a highway traffic lane dividing line or along road edges or the like to assist the night driver.
2. The Prior Art
Throughout the history of motor vehicle travel over paved road surfaces, many reflective devices for traffic guidance have been devised. While it is true that these have included an acceptable or even advantageous feature here or there, no entirely satisfactory highway lane or road edge reflector has been proposed. This largely accounts for their absence from very many United States highways. Absent solutions to many of the disadvantages outlined below, it is expected that these devices will not gain the governmental approval necessary for their use in a consistent interstate system of reflector lane demarcations and warnings.
The prior art describes numerous reflectors that include housings to be secured to a road surface and to house reflective lenses therein. In some, the lenses are exposed to tires passing over the housing. This abrades the lenses with a resultant decrease in reflectivity. In others, the reflecting lenses are sufficiently deeply recessed within the housing to prevent this, but only a narrow channel or opening is provided for incident light to reach the recessed lenses and for reflected light to be returned to an oncoming vehicle. The result is the reflector can be seen through only a relatively narrow angle, and consequently, visibility of these reflectors down a highway curve is lessened. Likewise, if the angle upward of reflected light is restricted, the reflectors visibility in hilly terrain decreases. In other prior art reflectors, even those in which the reflective lenses are adequately recessed so as not to be abraded by the passage of tires over the reflector, the reflector housing are often hollow shells insufficient to withstand the abuse of high speed truck traffic, snow plow blade encounters, and the impact of a tire that skids into the housing rather than rolling over it.
Often in the housings of prior art reflectors, a gradual rise of the reflector housing from the road surface in the direction of traffic flow is afforded while, in the transverse direction, the reflector housing arises abruptly from the road. In such reflectors, no thought appears to have been given to the skidding of a two wheeled vehicle as a result of a tire's edge meeting an abrupt parallel ridge.
Some prior art reflectors give attention to cleansing the reflecting lenses. In one instance, rainwater is directed over the lenses, but rainwater incident on the reflector housing is made to flow along the housing surface through a channel and onto the lenses. No provision is made to permit falling rain to impact the reflector lens surfaces first and without any intervention or redirection of the rainfall so that the considerable force developed by the raindrop's earthward fall can contribute to the cleansing of a lens deeply recessed protectively in a housing.
In several instances, the prior art points to the considerable damage that snowplow blades do to reflectors. In no instance, however, is the suggestion made that snowplow impacting be entirely avoided by providing a reflector with a separate recessed base residing entirely beneath the road surface and an easy to remove upper housing that carries the reflective lenses. Where snowplow damage is particularly severs, then, removal of the upper housing throughout the snow season is the answer.
Often the reflectors of the prior art must extend well above the surface of the road to provide a reflector lens of adequate size. Lower reflectors may suffer from thinner, weaker housings or from lenses too tiny to be visible at any great distance.
Many of the reflectors suggested in the prior art lack protection from theft of either the entire reflector housing or the reflector lens elements and so are particularly vulnerable to vandals. Others suggested in the art appear to be insufficiently secured and thus easily, accidentally dislodged.
So, although a number of reflectors have been described in the prior art with one or more desirable characteristics, none, to this time, has provided the combination of features necessary to overcome the many failings outlined above.